Microwave-assisted combustion synthesis of α-alumina and magnesium aluminate spinel nanocomposite powders

Abstract

Microwave-assisted combustion synthesis of α-alumina-magnesium spinel nanocomposite powders from a route using ammonium aluminum carbonate hydroxide (AACH) as a precursor was studied, γ- to α-phase transformation temperature of microwave-assisted alumina composite powders is lowered by 100°C compared to that of normal heat-treated alumina composite powders. The crystallite size of the microwave-assisted composite powders was considerably decreased from 42 nm to 29 nm compared to that of the normal heat treated composite powders. Nanosized α-alumina-magnesium aluminate composite powders were successfully synthesized by microwave-assisted combustion under nitrogen atmosphere at 1050°C.